JP2003149073A - Method and device for detecting defectively sealed package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a defectively sealed package detecting device that can detect defectively sealed food packaging bags regardless of the volume variation of gases enclosed in the bags. SOLUTION: This detecting device is provided with a pressing means 8 which applies a fixed load to a food packaging bag 4 and a measuring means 54 which measures the displacement of the bag 4 when the pressing means 8 applies the load at least at two spots. The device is also provided with a processing section 66 which discriminates the displacement of the bag 4 measured by means of the measuring means 54 by converting the displacement into a relative rate of change, and comparing the rate of change with a preset threshold. The pressing means 8 has a transport mechanism 10 having a pressing surface which applies the load to the bag 4 and a driving mechanism 16 which automatically operates the mechanism 10. In addition, the pressing surface is provided with a parallel crank mechanism 40 which can move upward and downward in parallel with a transport surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting a defective packaging seal, which automatically detects, on a production line, a sealing defect of a package in which food such as potato chips is sealed together with an appropriate amount of gas.

[0002]

2. Description of the Related Art When packaging foods that are packed in a unit amount, foods such as potato chips and rice crackers that are easily cracked and easily moistened should be packed in a packaging bag that contains an appropriate amount of gas such as air together with the foods. It is put and sealed. At this time, if there is a poor seal or holes in the packaging bag, the quality of the food may be deteriorated because the food is spoiled, moistened, or the gas inside the food was reduced, resulting in the shape of the food being lost. It becomes a factor. Therefore, in order to prevent such poor quality, it is important to maintain the airtight state inside.

Therefore, it is necessary to detect defective packaging and sealing of a packaging bag in which food and gas are enclosed together. The inspection of the sealed state is performed by checking whether or not the enclosed gas leaks when the packaging bag as the subject is pressed with a constant load. As an inspection device, the packaging bag to be inspected is conveyed on a belt conveyor, the side portion of the packaging bag is held down, the height of the central portion is measured twice, and the heights are compared. There is one (Japanese Utility Model Publication No. 7-19112). In this conventional technique, when the difference between the first measurement value and the second measurement value is large, the packaging bag has a seal defect somewhere and the gas content leaks out. Is considered to be present. Therefore, the packaging bag determined to have leakage is detected as a defective seal.

[0004]

However, the volume of gas enclosed in the packaging bag together with food is not always constant. Therefore, in the conventional technique, there is a case in which a non-defective product is determined to be defective depending on the capacity enclosed in the packaging bag. This is because the enclosed food itself has a constant internal volume, but at the same time, it is extremely difficult to control the amount of gas enclosed in the packaging bag to a constant amount, and the volume of the enclosed gas fluctuates greatly. Therefore, when there is a difference in the amount of gas enclosed in individual packaging bags in the same food packaging, the difference in the measured value is larger as the content amount is larger, and conversely, the measured value is smaller for those with less content amount. There is a problem that it is difficult to make a difference.

In order to reliably detect a defective product, the displacement difference of the defective product having a small amount of gas is used as a reference. Generally, the packaging bag is made by stacking the upper and lower films on both ends and welding them together. When an external pressure is applied, its shape changes every moment as it approaches a sphere, and normally, even if it is a good product, there is a slight difference between the first measured value and the second measured value. Therefore, when the displacement difference of a defective product with a small amount of gas is used as a reference, a product with a large internal volume is more likely to be judged as a defective product even if it is a good product, and a difference with a small internal volume is small. Therefore, there is a risk that a defective product is determined to be a good product.

Further, the conventional package seal defect detecting device uses an elastic body such as a spring as a means for applying pressure in a mechanism that presses both sides of the packaging bag in the vertical direction at regular intervals, and the stroke of the elastic body is used. It is difficult to inspect packaging bags that are out of the range. The vertical interval can be adjusted, but the interval cannot be varied step by step when continuously inspecting foods of the same type. Therefore, in the same type of food,
When inspecting packaging bags with different contents of enclosed gas, packaging bags with a large amount of content will be subjected to greater pressure, and the originally good seal can be damaged or crushed. There is a nature. In addition, regarding a packaging bag with a small amount of contents, both sides may not be pressed properly, and it is considered that the quality is not correctly determined because the measured value is not valid.

Further, the vertical adjustment of the means for pressing the side portion in the above case is performed by moving the belt conveyor for conveying the packaging bag up and down. Therefore, it is necessary to incorporate a conveyor belt conveyor into the package seal defect detection device, and the scale of the device must be large.

In view of the above-mentioned problems, the present invention provides a package and seal defect detecting apparatus which is capable of detecting a package and seal defect in a food packaging bag regardless of the fluctuation of the internal volume of the enclosed gas and has a small and simple structure. It is intended to be provided.

[0009]

In order to solve the above problems, a method for detecting a defective packaging sheet according to the present invention provides a method for detecting a height of a packaging bag when the packaging bag is pressed at least at two points in a continuous transport path. It is characterized in that the quality is determined by comparing the ratio between the height difference and the initial height with a preset determination threshold value.

In the quality judgment, it is also possible to multiply the ratio of the height difference and the initial height by a set multiple and compare it with a preset judgment threshold value to make a quality judgment. The packaging seal defect detecting device according to the present invention is provided with at least two places, a pressing means for applying a load to a food packaging bag, and a measuring means for measuring the displacement of the packaging bag when the pressing means presses, The displacement measured by the measuring means is converted into a ratio of the relative height difference and the initial height, and the ratio of the height difference and the initial height is compared and compared with a preset determination threshold value. Is characterized by.

Further, the carrying pressing means has a carrying mechanism having a pressing surface for applying a load to the packaging bag, a drive mechanism for automatically operating the carrying mechanism, and the pressing surface moves up and down in parallel with the carrying surface. And a parallel crank mechanism to obtain.

[0012]

According to the above, the detection of the sealing failure of the food packaging bag containing the gas is performed twice on the same continuous conveying surface by measuring the height of the packaging bag when a load is applied to the packaging bag. The ratio between the height difference of the packaging bag and the initial height, that is, the rate of change in height, is calculated and compared with a preset threshold value. By calculating the rate of change in this way, the amount of gas leaked from the packaging bag is relatively determined. Therefore, it is possible to determine the amount of gas leaked from the packaging bag regardless of variations in the internal volume.

Further, by providing the parallel link mechanism in the pressing means, the weighted surface with respect to the packaging bag can always be maintained in parallel and the measurement accuracy can be improved. It should be noted that by using a pneumatic cylinder as a cushioning function in the ascending / descending portion of the parallel link mechanism of the package seal defective product detection device according to the present invention, it is possible to reduce vibration or impact on the pressing surface when the packaging bag is pressed. Therefore, it is possible to avoid damage to the packaging bag due to an impact when it is pressed. In addition, the stroke of the gas pressure cylinder is provided with a width to prevent erroneous disconnection of the pass / fail judgment due to insufficient pressure on the packaging bag.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Specific embodiments of the defective package seal detection device 2 will be described below in detail with reference to the drawings. FIG. 1 is a front view and a side view of a defective package seal detection device 2 according to the present embodiment, and FIG. 2 is an explanatory view of the device.

The main configuration of the packaging seal defect detecting device 2 according to the present embodiment is as follows. In the processing line or the like, the packaging bag 4 is conveyed by the conveyor belt conveyor 6. On the conveyor belt conveyor 6 having the same continuous surface as described above, the pressing means 8 for applying a load to the packaging bag 4 is installed at two positions before and after along the conveying line at intervals, and the individual pressing means 8A, Measure the height of the packaging bag when pressed in 8B. The values measured by the pressing means 8A and 8B are compared with a determination threshold value set in advance by the processing unit 66 to determine the quality of the packaging seal state. At this time, the packaging bag 4 pressed on the conveyor belt conveyor 6
In order to smoothly convey the sheet, the pressing means 8 is provided with a conveying mechanism 10 that moves in the same direction as the conveyor belt conveyor 6 on the pressing surface. Further, in the present embodiment, the air cylinder 60 is provided as a gas pressure cylinder, and has a cushioning function for cushioning the impact at the time of pressing.

The packaging seal defect detecting device 2 according to the present embodiment is installed above the conveyor belt conveyor 6 which conveys the food packaging bag 4, and the packaging bag 4 conveyed on the conveyor belt conveyor 6 is placed above. The pressing means 8 is installed so as to press from above. The pressing means 8 determines the area of the pressing surface so that the load is applied to the entire packaging bag 4. In this embodiment,
The pressing means 8 is an auxiliary belt conveyor 14 having a width and a length of about 300 mm. The reason why the pressing means 8 is formed on the auxiliary belt conveyor 14 is that the pressing surface is in contact with the conveyed packaging bag 4 while applying a load, so that frictional resistance may hinder the transportation or cause the packaging bag to be transported. This is because there is a risk that 4 may be damaged. That is, by providing the transport mechanism 10 at the pressing portion, the auxiliary belt conveyor 14 is caused to have a movement in the same direction as the transport of the packaging bag 4.

The auxiliary belt conveyor 14 is provided with a drive mechanism 16 for operation. That is, the drive motor 18
Is used to move the pressing surface of the auxiliary belt conveyor 14 in the conveying direction of the packaging bag 4. When the drive motor 18 is attached, the stays 20 are provided on both side surfaces of the auxiliary belt conveyor 14, and the support plates 22 are attached to the stays 20. The support plate 22 is a flat plate having an area slightly smaller than the pressing surface of the auxiliary belt conveyor 14, and is installed parallel to the pressing surface. The drive motor 18 is fixed to the support plate 22 by a bracket 24 in the forward direction in the transport direction. Shaft of drive motor 18 and auxiliary belt conveyor 1
The pulley 26 is provided on the front shaft in the transport direction of No. 4, and the drive belt 28 is stretched over the pulley 26. Therefore, the power of the drive motor 18 is changed to the auxiliary belt conveyor 14
And the auxiliary belt conveyor 14 is interlocked with the conveyor belt conveyor 6 to reduce the frictional resistance between the auxiliary bag conveyor 14 and the packaging bag 4.

In order to attach the above-mentioned mechanism to the conveyor belt conveyor 6, the fixing plates 32 formed by bending the strip plate member into an L-shaped cross section are attached to both side surfaces along the conveyor direction of the conveyor belt conveyor 6. The length of the fixing plate 32 is slightly longer than that of the auxiliary belt conveyor 14. On the fixed plate 32, columns 34 are erected one on each side of the conveyor belt conveyor 6 before and after in the conveying direction. The top plate 36, which is slightly larger than the auxiliary belt conveyor 14, is attached to the upper part of the pillar 34 that stands up in this way. The above-mentioned auxiliary belt conveyor 14 from the top plate 36
Etc. are suspended and attached. At this time, the auxiliary belt conveyor 14 and the like are installed so that the pressing surface of the auxiliary belt conveyor 14 is parallel to the transportation surface of the transportation belt conveyor 6 at a constant interval. It is appropriate that the distance from the conveying surface of the conveyor belt conveyor 6 to the pressing surface of the auxiliary belt conveyor 14 is set to be slightly lower than the height of the packaging bag 4 which is the object, and the packaging bag 4 pushes up the pressing surface. Is. In order to make such vertical adjustments, a plurality of grooves are formed in a part of the columns 34 installed on all sides,
The position of the top plate 36 can be adjusted step by step depending on the position when it is pressed by a stopper or the like, or a screw-shaped groove is formed in the lower portion of the column 34 and the fixing plate 32, and these are screwed together to form the column 34 It is also possible to have a function such as adjusting the vertical direction.

By the way, in order to measure the height of the packaging bag 4 when the packaging bag 4 is pressed and to evenly press the packaging bag 4, it is necessary to install the pressing surface horizontally. Therefore, the parallel crank mechanism 40 is provided so that the pressing surface of the auxiliary belt conveyor 14 swings horizontally.

The parallel crank mechanism 40 is composed of a fixed arm 42 and a mounting arm 44 which are vertically arranged, and a buffer arm 46 and a support arm 48 which are horizontally arranged. The vertical arm is formed as a flat plate, and the mounting portion is bent in an L shape so as to be fixed to the top plate 36 and the support plate 32, respectively. These arms are paired, and a lateral buffer arm 46 and a support arm 48, which are formed of square bars, are sandwiched and connected.

The respective arms are connected to each other as follows. A bearing 50 is fitted into each of the fixed arm 42 and the mounting arm 44 in the vertical direction by punching at the connecting position. Through holes are formed at the connecting positions in the lateral buffer arm 46 and the supporting arm 48, and the connecting shaft 52 is inserted therein. The connecting shaft 52 has a shaft portion formed to have a length equal to the width of the square bar of the horizontal arm, and the bearing portion is inserted into the bearing 50 fitted in the vertical arm. That is, the vertical and horizontal arms rotate about the connecting shaft 52. At this time, since the connecting distances between the facing arms are made equal, the angular velocities of the facing arms become equal to each other. Therefore, the facing arms, that is, the vertical fixed arm 42 and the mounting arm 44, and the horizontal buffer arm 46 and the support arm 48 perform the swinging motion while keeping parallel to each other.

The arrangement of these arms will be described. A pair of fixed arms 42 are vertically attached to the support plate 22 at the center of the support plate 22 so as to face each other. A lateral support arm 48 is attached so as to be sandwiched by the fixed arm 42, and a buffer arm 46 is similarly sandwiched and attached above the fixed arm 42, slightly below the center of the fixed arm 42. The carrying inlet side of the packaging bag 4 of the support arm 48 and the buffer arm 46, that is, FIG.
On the left side of (1), a lateral arm is sandwiched by a pair of mounting arms 44 to be mounted. The mounting arm 44 is fixed to the top plate 36 vertically. Therefore, since the fixed arm 42 in the vertical direction moves in parallel with the mounting arm 44, the fixed arm 42 makes a swing motion in the vertical direction, and the pressing surface of the auxiliary belt conveyor 14 installed vertically to the fixed arm 42. Can move vertically while keeping horizontal.

A displacement sensor 56 is used as the measuring means 54 for measuring the height of the pressing surface of the auxiliary belt conveyor 14.
Is attached to the lower surface of the top plate 36, which is above the fixed arm 42. A suitable type of the displacement sensor 56 is a non-contact type such as an optical type. The upper part of the fixed arm 42 is covered with a plate 58 so as to be horizontal, and the distance to the plate 58 is measured by a displacement sensor 56 attached to the top plate 36. Because the fixed arm 4 with the plate 58 attached
Reference numeral 2 is a unit that vertically swings by the parallel crank mechanism 40, and the auxiliary belt conveyor 14 is fixed to the fixed arm 42 via the support plate 22, so that the displacement amount of the auxiliary belt conveyor 14 is Fixed arm 4
This is because the displacement amount is 2, and therefore the displacement amount of the auxiliary belt conveyor 14 can be known by measuring the displacement amount of the plate 58.

By the way, when the packaging bag 4 is conveyed and comes into contact with the pressing surface of the auxiliary belt conveyor 14, vibration is generated as a reaction and an excessive load is applied to the packaging bag 4 to damage it or the height of the packaging bag 4 is increased. It can be assumed that an accurate measurement value cannot be obtained. In order to solve these problems, an air cylinder 60 is provided, and vibration is absorbed by using suction / exhaust resistance to reduce responsiveness.

The air cylinder 60 is attached to the right side of the top plate 36, that is, in front of the carrying direction in FIG. 1 (1). The top plate 36 is provided with a through hole, and the air cylinder 60
The cylinder shaft is inserted so that the cylinder shaft portion of the above protrudes below the top plate 36, and the air cylinder 60 is fixed to the upper surface of the top plate 36. The buffer arm 46 is perforated, the bearing 50 is fitted therein, and the auxiliary arm 62 having the connecting shaft 52 inserted therein is connected to the buffer arm 46. The cylinder shaft is connected to the auxiliary arm 6
It is fixed to the upper part of 2, so that the cylinder shaft and the auxiliary arm 62 can swing vertically like the fixed arm 42 and the mounting arm 44.

Here, the above-mentioned package seal defect detecting device 2 is equipped with the auxiliary belt conveyor 14, the drive motor 18, etc., and a large load is applied to the portion suspended by the parallel crank mechanism 40. However, if the load W for pressing the packaging bag 4 is too large, there is a risk of damaging the packaging bag 4, so the weight applied to the pressing surface of the auxiliary belt conveyor 14 must be reduced. Therefore, the weight 6 is placed on the left side of the buffer arm 46, that is, on the rear side in the transport direction.
4 is attached and it works as a counter weight. As a result, the balance is maintained and the load applied to the pressing surface of the auxiliary belt conveyor can be reduced.

The above-mentioned pressing means 8 are arranged at least at two positions in the continuous transport path. The values measured by the measuring means 54 by the respective pressing means 8 are
The data is sent to the processing unit 66 and subjected to arithmetic processing.

Here, the operation of the packaging and sealing defect detecting device 2 in the present embodiment will be described. As shown in FIG. 2 (2), the packaging bag 4 as the subject is conveyed on the conveyor belt conveyor 6, contacts the auxiliary belt conveyor 14A of the first pressing means 8A, and is promoted by the upper and lower belt conveyors. Attracted to the detection area. The pressing surface of the auxiliary belt conveyor 14A is set to be slightly lower than the height of the packaging bag 4 in the initial setting, but this is pushed up by the thickness of the packaging bag 4. As the pressing surface rises, the fixed arm rises vertically, and the buffer arm 46 tilts upward to the right around the connection point with the mounting arm 44. However, the right end of the buffer arm 46 is connected to the air cylinder 60, and the air cylinder 60 slowly rises due to the internal exhaust pressure resistance, so that the entire pressing means 8A is slowly lifted. The height S1 of the pressing surface at this time is measured by the displacement sensor 56A and stored in the processing unit 66. After that, when the packaging bag 4 is pushed out of the detection area, the auxiliary belt conveyor 14A of the pressing means 8A automatically descends by its own weight and returns to the initial setting position.

The packaging bag 4 is further conveyed by the conveyor belt conveyor 6 and comes into contact with the auxiliary belt conveyor 14B of the second pressing means 8B, and through the same process as the above-mentioned first pressing means 8A, the pressing surface The height S2 is stored in the processing unit 66. At this time, the flow chart shown in FIG. 3 is calculated by the processing unit 66, and the quality of the sealed state of the packaging bag that has passed the detection area is determined. The processing operation of detecting a defective sheet in the packaging bag will be described below based on the measured values.

The displacement amounts S1 and S2 measured by the first and second packaging sheet defect detecting devices 2 are compared.
When S2 is equal to or larger than S1, it is considered that there is no leakage of the gas enclosed in the packaging bag 4, and the subject is determined to be a good product.

If S2 is less than S1, then S1 and S2
When the difference St is equal to or larger than the preset maximum allowable value Am, the leaked amount exceeds the ABS maximum allowable amount Am regardless of the volume of the gas enclosed in the packaging bag. Will be there. That is, the amount of leakage is large, and the subject is determined to be defective.

Here, the displacement amount St is the ABS maximum allowable difference Am.
When it is smaller, the ratio of the displacement amount St, which is the difference in height, to the initial height, that is, the change rate S is compared with the determination value D.
At this time, the change rate S and the determination value D are expressed by the equations 1 and 2.

[Equation 1]

[Equation 2] That is, the rate of change S is obtained by dividing the displacement amount St by S1, and the rate of change S is expanded by multiplying this by an integral multiple (N times), and the failure rate of the sheet is examined by examining the rate of gas leakage. Is determined. At this time, as a criterion for judging the judgment value D, a judgment threshold value Dt is set in advance, and judgment of pass / fail is made based on the judgment threshold value Dt.

When the judgment value D is equal to or larger than the predetermined judgment threshold value Dt, it is judged that the leak rate of the gas enclosed in the packaging bag exceeds the predetermined rate. Therefore, regardless of the volume of the enclosed gas, the sample is determined to have a large leak rate and is determined to be a defective product.

If the determination value D is less than or equal to the determination threshold Dt, the subject is determined to be a non-defective item. As shown in Fig. 4, when the packaging bag is sandwiched between two parallel surfaces and pressure is applied and the distance between the two surfaces is measured as in this method, even if the same amount of gas leaks from the inside, Since the packaging bag having a large amount has a shape close to a sphere, the displacement amount St becomes large. On the other hand, the displacement St of the packaging bag having a small content is small. Further, in the measurement by the mechanism using the spring, the pressing force also changes, and this tendency becomes more severe.

In this way, by comparing the amount of gas considered to have leaked with the change rate S, the packaging bag 4, which is the subject whose quality is difficult to determine due to variations in the internal volume, can be analyzed more accurately. It is possible to Therefore, it is possible to avoid the situation in which a defective product is distributed as a product due to an erroneous judgment of quality, which is useful for quality improvement and at the same time reduces the disadvantage of disposing a defective product as a defective product. it can.

Further, since the packaging bag 4 is pressed by its own weight of the pressing means 8 itself, a substantially constant pressure can be applied regardless of the amount of gas. That is, when the amount of gas is large, the gap between the pressing surface of the auxiliary conveyor belt 14 and the conveyor belt 6 is large, and when the amount of gas is small, this gap is small. When the pressing is performed using an elastic body such as a spring, the pressing changes in proportion to the size of the interval, but in the present invention, the same pressure can be applied regardless of the size of the interval. The range in which the pressing surface oscillates in the vertical direction is determined by the stroke of the air cylinder 60 connected to the parallel crank mechanism 40. Therefore, a wider range of oscillating motion is possible than when an elastic body such as a spring is used. Even when there is a large variation in the internal capacity of the packaging bag 4, the packaging bag can be dealt with without damage.

Since the defective package sealing detection device 2 is a mechanism for pressing the packaging bag 4 only from above, it is not necessary to install a mechanism for pressing the packaging bag 4 from below on the conveyor belt conveyor. As a result, the packaging seal defect detection device 2 can be downsized and simplified because the space for the conveyor belt conveyor 6 is unnecessary. In addition, it is also possible to directly install the defective packaging sheet detection device 2 on a processing line of a factory or the like, which is useful for space saving.

In the present embodiment, the air cylinder 60 is used as the gas pressure cylinder, but it is needless to say that the same effect can be obtained with a cylinder using other gas such as a hydraulic cylinder.

Further, by mounting the gas pressure cylinder on the pressing means, the vertical amplitude due to the variation of the inner volume can be controlled by the gas pressure cylinder, so that an equal load can be applied regardless of the inner volume. became. Therefore, the packaging bag may be crushed due to excessive load,
Further, it is possible to eliminate the risk of product damage or erroneous detection results due to the characteristics of individual products, such as incomplete pressing due to the small amount of contents. Since the pneumatic cylinder control can detect the sealing failure of the packaging bag by the load from one direction, the detection device can be attached to the food processing / conveying path, and the step and the place for detecting the defective product can be omitted.

[0040]

According to the present invention, the seal defect of the product is judged by substituting the rate of change, not the measured value, for the difference in the internal volume when the product is pressed. In this way, by setting the rate of change to be judged as a relative numerical value, it is possible to make a fair judgment regardless of changes in the internal capacity. Therefore, in the same type of food, even if the volume of the enclosed gas varies, it is possible to judge the quality of the sealed state according to the individual volume.

[Brief description of drawings]

FIG. 1 is a front view and a side view of a defective package seal detection device according to the present embodiment.

FIG. 2 is an explanatory diagram of a defective package seal detection device according to the present embodiment.

FIG. 3 is a flowchart of a package seal defective product detection inspection.

FIG. 4 is an explanatory diagram of a displacement amount of a packaging bag due to a difference in internal content.

[Explanation of symbols]

2 ………… Package seal defect detection device, 4 ………… Packaging bag, 6
……… Conveyor belt conveyor, 8 ………… Pressing means, 10…
...... Conveying mechanism, 14 ………… Auxiliary belt conveyor, 16 ……
...... Drive mechanism, 18 ...... Drive motor, 20 ...... Stay, 22 ...... Support plate, 24 ...... Bracket 26
...... Pulley, 28 ………… Drive belt, 32 ………… fixing plate, 34 ………… post, 36 ………… top plate, 40 ………… parallel crank mechanism, 42 ………… fixing arm, 44 ………… Mounting arm, 46 ... Buffer arm, 48 ... Support arm, 50 ... Bearing, 52 ... Connection shaft, 54 ...
Measuring means 56 ... Displacement sensor 58 ... Plate, 60 ... Air cylinder, 62 ... Auxiliary arm,
64 ......... weight, 66 ......... processing section.

Claims (3)

[Claims] 1. At least 2 in a continuous transport path
Measure the height of the packaging bag when pressing the packaging bag at the location,
A method for detecting defective packaging seals, comprising performing a quality determination by comparing a ratio between the height difference and the initial height with a determination threshold set in advance. 2. At least two pressing means for applying a load to a packaging bag that is continuously conveyed on the same surface, and a height measuring means for the packaging bag when the pressing means presses the packaging bag.
Displacement measured by the measuring means is provided at a location and converted into a ratio between the height difference and the initial height, and the quality is judged by comparing the ratio between the height difference and the initial height with a preset judgment threshold value. An apparatus for detecting defective packaging seals, comprising a processing section. 3. The pressing means includes a conveying mechanism having a pressing surface for applying a load to the packaging bag, a drive mechanism for automatically operating the conveying mechanism, and the pressing surface can move up and down in parallel with the conveying surface. The defective package seal detection device according to claim 2, further comprising a parallel crank mechanism.